This is the question. May I know that event quoted below? Hey! I gotta ask! ES "there is an event that happens in between these block orders being filled that will not only tell you what direction the intended position is but it will also verify that it is a commercial block order"
sure say you place a x1000 block order in a 30 tick range to be filled - you will get half of your order filled and then the price will trade very light volume a few ticks lower if your block order was a buy or a few ticks higher if your block order was a sell.
these few ticks are insiders who saw your order go in and they are buying lower and or selling higher to sell or buy back to you because they know they have a guaranteed buyer or seller which is you.